A tealight is a candle in a thin metal or plastic cup so that the candle can liquefy completely while lit. They are typically small, circular, wider than their height and inexpensive. Because of their small size and low level of light, multiple tealights are often burned simultaneously. Longer-burning tealights may be called nightlights.Tealight candles are essentials in any home.Use them to heat essential oils in aroma lamps, to warm up teapots and fondue dishes or even to decorate an area or ledge that is short on space. You can also float them in water filled bowls or vases to add to an ambient party atmosphere.